Drilled/slotted Rotors

[Landshark]

Originally posted by Ron Mummert



While we're here - can cryogenic rotors be "turned", or is this a REALLY stupid question?

Ron(duh?)

there aren't any stupid questions, just stupid people they need to be turned with a cryo-frozen lathe. ok, really, i don't see why not, but i hope they never need it.

[Landshark]

Originally posted by Beav
From what I've read Ron they can be turned. Supposedly the freezing goes 'to the bone', so to speak.

At first I thought they might be on to something, but the more I think about it the more I think that they're probably as good as placing magnets around your gas line. I guess my biggest problem is that warping is caused by density variations and freezing isn't about to cure that. A better process in casting them would be the ticket. But the manufacturers are selling them like hotcakes at ridiculous prices already, why should they change anything?

i saw a show on cryo-freezing (Discovery Channel?) a while back, and its not a gimmick. i don't remember a whole lot from it, but people were freezing whole engine blocks, rifle barrels, etc. the freezing packs the molecules in tighter making the metal denser and harder.....or something like that

[Beav]

I can agree with that, however the warping comes from density variations in the rotor. As it heats and cools the denser portions are slower to move than the not-so-dense portions. The molecules may be more tightly packed, but they will still be denser in some areas. That's why I'm reluctant to buy into them, at this time anyway.

[Ron Mummert]

Originally posted by Beav
I can agree with that, however the warping comes from density variations in the rotor. As it heats and cools the denser portions are slower to move than the not-so-dense portions. The molecules may be more tightly packed, but they will still be denser in some areas. That's why I'm reluctant to buy into them, at this time anyway.

So you're saying the warpage problem isn't really cured; it's just a "higher quality" warpage. That settles it. I'm going back to drums at all 4 corners.

Ron.

[Beav]

Well let's just say IMHO that freezing will make them tougher and less prone to wear from harsh friction materials. The best I can speculate on the warpage issue is that they may be more 'warp-resistant' than 'warp-proof'.

BTW, the NASCAR set used drums for a long, long time - even after disc brakes were mature products.

[ensteele]

Beav -

So what's wrong with placing magnets around your gas line? I get 150+ more Horse Power, and 10 more miles per gallon! You should see what happens when I put them around my rear view mirror!

[Trevor]

Beav it appears to me that warping problems started with the advent of ventilated discs (rotors) and solid discs did not warp the same. Your explanation in respect of variations in density or cross section causing uneven heating and cooling adds up in every respect.

Forty years ago I raced one of the first disc brake equiped cars and the brakes were outstanding in all respects. On a dull day they could be seen running dull red. Absolutely no problems with warping and no brake fade but I must say that the rotor diameter was adequate in relation to the weight of the car.

[vkykam]

Yes, Cryo rotors can be turned. I've had to do it.

The theory behind cryo treating them is that it changes the molecular structure of the metal, that somehow it creates a more dense and consistant material. The consistancy I think is their claim to the reduction of warpage. I'm no engineer, so I can't explain it better.

My cryo rotors warped because my calipers started to stick. Calipers have been rebuilt, rotors have been turned, and for the first month, there's no warpage. Then it started to rear its ugly head again. It's a minor pulsation at this point, and only when the rotor is hot, and it hasn't gotten any worse. Oh well.

VK
1.3 cents

[dromano]

Originally posted by Landshark


i'm looking at a picture of a 962c factory racecar right now and it has "drilled"(cast hole) rotors. those idiots - what are they thinking!?!?!
the new rotors on the 911 twin are ceramic - don't know if they use them for factory racing, though. i'm guessing yes.

The ceramic rotors reach 200 degrees at the hottest. The rest of the heat from braking transfers to the metal in the calipers and connected parts.

www.movit.de/rahmen/ceramic.htm

[mattski]

I saw some highlights of a road rally on Speed channel and portions of the race were at night. They showed some Subies with an interesting wheel "mod". They were lit up by glowing red rotors.

That has to be over 1000 degrees F!

Kelli, this is even better than your neons.

[SVX_MY_BABY]

Originally posted by Beav
But the manufacturers are selling them like hotcakes at ridiculous prices already, why should they change anything?

Beav, don't know where you are getting your quotes, but Dean at ART got me my rotors & pads substancially cheaper than OEM even after shipping from California and Customs clearance.

As an aside, I had gone through 2 sets of front rotors after about 79,000 km (Yes, I like to drive hard on the twisty roads which abound here plus the salt used on our winter roads rusted them badly.) I now have 30,000 km & 2 winters on the cryo's & they seem like new. Pads are also looking good.

[Beav]

Wrong context. I was referring to the ridiculous amount of money required to buy a seven pound hunk of cast iron. (o.k., maybe more, maybe less) Rotors are a long way from rocket science, but one would never know, considering their price. I wasn't singling out frozen rotors, I was referring to all rotors.

[Ron Mummert]

[QUOTE]Originally posted by Beav
[B]Wrong context. I was referring to the ridiculous amount of money required to buy a seven pound hunk of cast iron.


How 'bout the bucks spent for a dram of crytallized carbon that serves the purpose of making Ronnie Mervis a veddy happy campaah? Ever try to stop an SVX with a pinkie ring? Ah... The Human Condition. Gotta' marvel at it every day.

Ron.

[Paisan]

Originally posted by Beav
BTW, the NASCAR set used drums for a long, long time - even after disc brakes were mature products.

nAScar is also still using carburated pushrod engines! nAScar is funny if they were only real cars instead of shells it might actually be interesting, not to mention 500 miles of all left turns gets boring after lap # 3

-mike

haha. True that. Nascar blows. Plus, if you kick too much ass, they ban you (Charger Daytonas, Superbirds). >:|

- Ca$h